With the emergence of telecommunication services, various technologies have been developed for communicating data in telecommunication networks. One example of such a technology is WCDMA (Wideband Code Division Multiple Access), which is capable to distribute as well PS data, (Packet Switched), as CS data (Circuit Switched).
In this description, the term “User Equipment” (UE) will be used to denote any suitable communication terminal adapted to communicate with a radio base station. A UE, may be implemented as a mobile phone, a PDA (Personal Digital Assistant), a handheld computer, a laptop computer, etc. A “radio base station” may be implanted as a NodeB, an eNodeB, a repeater, etc.
In telecommunication networks, as well PS data as CS data is communicated between UE:s and a core network. Typically, a UE is associated to the core network via a radio access network (RAN). Logical connections, defined as “Radio Access Bearers” (RAB), are set up between each UE and the core network and serve both communication of PS data and communication CS data. RAB:s are dynamic and can change communication rate, and in the communication system Radio Access Network (RAN) communication resources, can be reallocated from one RAB to another RAB by a radio network controller, which is arranged to control communication in the communication network. In this description, the term “PS connection” denotes a logical connection applied for one PS data service of a UE, between the UE and the core network. Generally, each PS data service uses one respective PS connection, and a plurality of PS connections may be applied by the UE on an RAB set up between the UE and the core network. Moreover, typically, one or more CS data services for the UE may also apply the RAB. However, this description relates to PS data services, and the CS data services will not be further mentioned herein.
With reference to FIG. 1, a communication system 100 according to the prior art will now be described.
In the communication system 100, PS data is communicated between one or more User Equipments (UE) 102, 104, . . . , and a core network 110. A radio access network (not referred to) and a radio network controller 112 distributes PS data between the UE:s 102, 104, . . . , and the core network 110. When communicating PS data, the radio network controller 112 receives PS data from the core network 110 on a first communication link 114, and transmits the PS data intended for a specific UE 102 to a radio base station 106 on a second communication link 108, the radio base station 106 which serves the specific UE 102. The PS data flows through the radio network controller 112, and the PS data flow 118 is shown as a dotted line in the figure. Then the radio base station 106 transmits the PS data to the specific UE 102 on one or more PS connections (not shown in the figure) between the radio base station 106 and the specific UE 102. The PS connections are logic connections between the core network and the respective UE:s, 102, 104, . . . . Communication of PS data between the radio base station 106 and specific UE:s 102, 104 is illustrated by flash formed arrows in the figure. In the radio network controller 112, a resource manager 116 is arranged to control the RAN communication resources used to transmit PS data from the core network and select the radio base station 106 which currently serves the specific UE 102. When controlling the RAN communication resources, the resource manager 116 analyses the PS data flow 118 and allocates RAN communication resources to the PS connections, based on various predefined policies. Such policies may be defined based on Quality of Services (QoS) classes, end-users subscriptions, etc. Typically, a PS connection according to a higher QoS class and/or a more advanced subscription will be prioritised to get RAN resources allocated, than PS connections according to lower QoS classes or less advanced subscriptions.
Due to massive increase of packet switched data traffic in communication networks, there is a need to handle congestions of communicated PS data in the communication system, still providing enough communication resources to the end-users.